Methods of frequency-correction for systolic time intervals
- 30 Downloads
To judge the influence of drugs and diseases on systolic time intervals (STI), the connection to the covariate belonging to heart frequency has to be eliminated. For this purpose, we adopt linear dependency of the interval between the R-waves in the ECG and STI. In this paper, according to different medical questions, wellfitting correction formulae are derived, based on new biometric analysis of published data.
The methods used include L1-norm and L2-norm regression, rank-test connected regression of Theil and Sen, and rank-scores analysis of covariance.
It is concluded that the biometric methods must be well adapted to medical methods.
Key wordssystolic time intervals R-R interval linear dependency diagnostics clinical trials
Unable to display preview. Download preview PDF.
- 2.Weissler, A. M., J. R. Snyder, C. D. Schoenfeld, S. Cohnen: Assay of digitalis glycosides in man. Amer. J. Cardiol.17, 768–80 (1966).Google Scholar
- 6.Weissler, A. M. (Ed.): Noninvasive cardiology. Grune and Stratton (New York 1974).Google Scholar
- 8.Wolf, G. K.: May results of evaluative studies be falsified by using incorrect correction methods? Paper for the International Conference on STI (Graz 1978).Google Scholar
- 10.Belz, G. G., R. Erbel, K. Schumann, H. J. Gilfrich: Dose response relationships and plasma concentrations of digitalis glycosides in man. Europ. J. clin. Pharmacol.13, 103–11 (1978).Google Scholar
- 11.Barrodale, I., F. D. K. Roberts: Algorithm 478-Solution of an overdetermined system of equations in the L1norm (F4). Commun. ACM17, 319–20 (1974).Google Scholar
- 12.Theil, H.: A rank-invariant method of linear and polynomial regression analysis, I, II, III. Nederl. Akad. Wetensch. Proc.53, 386–92, 521–5, 1397–412 (1950).Google Scholar
- 14.Sen, P. K.: Estimates of the regression coefficient based on Kendall's Tau. JASA63, 1379–89 (1968).Google Scholar
- 15.Puri M. L., P. K. Sen: Nonparametric methods in multivariate analysis (John Wiley, New York, London, Sydney, Toronto 1971).Google Scholar